Trenching Machinery.

Chain excavators
Mini-excavators (up to 1.5 tonnes).

1.5 ton excavators are very popular as they can be towed by most 4 x 4 vehicles and vans.

With machine weight at 1500kg and trailer at 500kg (2 tons combined), the 1.5 ton excavator is eligible to be towed by a vehicle with a high enough rated train weight.
 

Machine example specification:
mm (ft-in)
Sprocket idler centres 1027 (3-4)
Undercarriage overall length 1384 (4-7)
Kingpost clearance 376 (1-3)
Tailswing radius 1028 (3-41⁄2)
Overall width of superstructure 980 (3-21⁄2)
Height over cab 2318 (7-7)
Ground clearance 158 (0-6)
Machine model 8014
mm (ft-in)
H Track gauge 742 (2-5)
I Width over tracks 972 (3-2)
J Transport length 3346 (10-113⁄4)
K Transport height with FOGS guard 2318 (7-7)
K Transport height without FOGS guard 2304 (7-61⁄2)
L Track height 366 (1-2)